[技术]Arizona眼睛模型 [复制链接]

简介 $t$Sh
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人眼光学模型可用来设计眼科用设备，光学系统注定了要与人眼一起使用。本文演示了这样一个模型：Arizona眼睛模型，在Jim Schwiegerling教授的书中有详细描述：《Field Guide to Visual and Ophthalmic Optics》。AZ眼睛模型达到了基于平均临床数据所决定的轴上和轴外像差等级。FRED文件包含了此眼睛模型及几个用来分析它的光源，并包括一个基于想要的屈光度来调整模型的内嵌脚本。 j8v8uZ;x  
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模型 8}I$'x  
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模型的定义如表1种所示，由半径、圆锥常数、折射率、阿贝数、到下一面的距离等一系列表面组成。一些参数由屈光度（A）来决定。 &|s
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在FRED中使用0屈光度来创建的，光瞳加在了透镜的前面。材料是创建一个新的材料并选择类型“Model Material”,输入的参数是nd和vd. `!obGMTQ<  
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光源 Y>dF5&(kb  
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多个光源定义来分析该模型的不同特性。图1显示了所以的光源和提示信息告诉您他们可以用来做什么。 Kr?TxhUHd  
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除了“Letter F”之外的所有光源的光线位置设定在了孔径光阑位置处，并增加了pre-propagation distance= -8。尽管光线在光瞳处创建，规定的传输方向相对于光线位置在pre-propagation distance之后。这意味着光束沿着Z轴在眼睛的前面以平行光入射，而不是在光瞳处入射。 Q1U\D  
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在往下看是内置的脚本用来修改屈光度，使其为4（250mm），光源“Letter F”在视网膜处生成一个字母为F的图像。绿色的光线聚焦的非常好而红色和蓝色光线有一点的模糊。使用Positions Spot Diagram分析工具来观察最为合适。 ]Z>}6!  
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视网膜的散射 V><,UI=,n  
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在散射文件中，有一个名为“Retina surface”的72%的反射型朗伯散射，它为视网膜的散射提供了一个粗略的近似。为了模拟来自视网膜的散射，改变自定义元件“Eye ball” 下的视网膜的表面从“halt all” 到”Allow All”。并使几何中“plane”可追迹。 0CWvYC%e  
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注意在视网膜的表面有散射重点采样规格定义，在“Scatter”标签的底部可获取该信息。“toward pupil”指定散射光朝向光瞳，半角度10度。 nXaC3W:"  
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脚本 7LfAaj  
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内置脚本使用对话框显示屈光度和光瞳直径的数值设置。使用FRED Basic脚本创建和使用对话框非常容易。图6显示了如何获取用户自定义对话框，如下图所示： ^6jV_QM#  
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如果“OK”按钮按下，将会核对对话框下面的代码行，如果点击取消则脚本终止。然后输入的参数赋予变量，如果此处是保留为空白，则使用默认值。因此，如果没有值输入并点击“OK”按钮，则脚本是以屈光度为0，光瞳直径为4mm来运行的。 EH-sZAv  
余下的脚本计算与屈光度有关的所有参数。 _jvxc'6  
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分析 *2ZjE!A  
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屈光度为4，光瞳直径为4mm，字母F点在视网膜上所成的像。 6{@w="VT  
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脚本代码 :W"~ {~#?  
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Option Explicit     'Remove this to enable non-dimensioned variables to be used. Z@yW bjE7Z  
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Dim entity As T_ENTITY @Y?#Sl*  
Dim op As T_OPERATION dydc}n  
Dim mat As T_MODELMATERIAL ;p.v]0]is  
Dim A As Double fIM,lt  
Dim pupilDiam As Double mJ<=n?{Z  
Dim eID As Long ~Q*%DRd&Z-  
Dim parID As Long @g|v
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Dim count As Integer  nI[os  
Dim taq As Double, Rant As Double, CCant As Double, Rpost As Double, CCpost As Double LY+@o<>  
Dim tlens As Double, nlens As Double #`~C)=-  
Dim curv As Double, conic As Double Q
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Dim ok As Long pk>^?MO  
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Sub Main n#mA/H;wV  
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    '用户输入对话框 t1]K<>g  
    Begin Dialog UserDialog 320,126,"Input parameters" ' %GRID:10,7,1,1 SP@ >vl+;  
        TextBox 220,21,40,21,.TextBox1 'default: 0 b}\N;D.{  
        Text 20,21,190,21,"Accommodation (in Diopters):",.Text1,1 } j<)L,  
        OKButton 40,91,90,21 9q)Kfz  
        CancelButton 190,91,90,21 x;w6na  
        Text 20,49,190,14,"Pupil diameter (4 mm default):",.Text2,1 {M3qLf~z#C  
        TextBox 220,49,40,21,.TextBox2 'default: 4 {baq+  
    End Dialog hC:n5]K  
    Dim dlg As UserDialog mD/9J5:  
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    ok = Dialog (dlg) }I2wjO  
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    If ok=0 Then    'cancel button was pressed >1s* at/h  
        Print "Execution cancelled." hZdoc<  
        End 5
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    End If m&xW6!x  
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    'Assign accommodation and pupil diameter & use defaults if field left empty -#7'r<I9@  
    If dlg.TextBox1 = "" Then >q#rw  
        A = 0           'Default accommodation ()2I#  
    Else ~Uu4=  
        A = CDbl(dlg.TextBox1) oxC[F*mD  
    End If 6O|@xvg  
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    If dlg.TextBox2 = "" Then 67VL@ ]  
        pupilDiam = 4   'Default pupil diameter NYt&@Z}]  
    Else "C}
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        pupilDiam = CDbl(dlg.TextBox2) !-ok"k0,u  
    End If . kQkC:~9  
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    Print " " nx@=>E+a  
    Print "Accommodation = " & A & " Diopters" gGvz(R:
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    Print "Pupil Diameter = " & pupilDiam & " mm" nv GF2(;l  
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    ' Calculate new parameters with accommodation ;>#wU'  
    taq = 0.55 + 2.97 - 0.04*A              'Aqueous thickness >5_2_Y$"  
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    Rant = 12.0 - 0.4*A                     'Radius of anterior lens m/Oh\KlIl  
    CCant = -7.518749 + 1.285720*A          'Conic constant of anterior lens VE#Wb7  
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    Rpost = -5.224557 + 0.2*A               'Radius of posterior lens S-P/+K6  
    CCpost = -1.353971 - 0.431762*A         'Conic constant of posterior lens 9K
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    tlens = 3.767 + 0.04*A                  'Lens thickness ks"|}9\%<  
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    nlens = 1.42 + 0.00256*A - 0.00022*A^2  'Lens index of refraction |h-QP#]/  
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    'Adjust parameters to account for accommodation OSlvwH%(EE  
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    '************************************************************************* H#NCi~M>3  
    'Aqueous thickness (Position of Lens) prYs $j  
    '************************************************************************* )+l\w3^6  
    eID = FindFullName( "Geometry.Arizona Eye.Lens" ) [.m`+  
    GetCustomElement eID, entity sA/pVU  
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    parID = FindFullName( "Geometry.Arizona Eye" ) os,* 3WO  
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    ' Delete any shift(s) in z 3 N.~mR  
    count = 0 aAJU`=u
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    While GetOperationCount(eID)>count '{E@*T/<.  
        GetOperation eID, count, op (}a8"]Z  
        If op.Type="ShiftZ" Then 9XPo3;  
            DeleteOperation eID,count PfreAEv,  
            count=count-1 plUZ"Tr  
        End If #OIcLEn%  
        count=count+1 DBPRGQ  
    Wend ZNf6;%oGG  
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    'Set new shift in yOphx07 (  
    op.Type = "ShiftZ" L%BNz3:Dt  
    op.val1 = taq (&}i`}v_  
    op.parent = parID #.it]Nv{  
    AddOperation eID, op :E_g"_  
    Print "Set aqueous humor thickness = " & taq-0.55 vI2^tX9  
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    '************************************************************************* >_o}  
    'Radius and conic constant of anterior lens Z3{>yYR+  
    '************************************************************************* ]vgB4~4#LP  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Anterior" ) 7N-
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    GetConic eID, entity, curv, conic X}tVmO?  
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    SetConic eID, entity, 1/Rant, CCant qp/v^$EA  
    Print "Set anterior lens radius = " & Rant & " and conic constant = " & CCant ])L A42|  
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    '************************************************************************* q8s0AN'@t'  
    'Radius and conic constant of posterior lens G]fRk^~  
    '************************************************************************* K@#(*."  
    eID = FindFullName( "Geometry.Arizona Eye.Lens.Posterior" ) %K\?E98M  
    GetConic eID, entity, curv, conic ,_yhz0.  
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    SetConic eID, entity, 1/Rpost, CCpost wW#}:59}  
    Print "Set posterior lens radius = " & Rpost & " and conic constant = " & CCpost 1jy9lP=  
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    '************************************************************************* .Jt[(;  
    'Lens thickness (Position of posterior lens surface) Eve.QAl|  
    '************************************************************************* 5$wpL(:R(  
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    parID = FindFullName( "Geometry.Arizona Eye.Lens" ) Z$0uH*h  
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    ' Delete any z-shift(s) O)ME"@r@:  
    count = 0 ^j"
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    While GetOperationCount(eID)>count wQwQXNG  
        GetOperation eID, count, op 1_\;- !t  
        If op.Type="ShiftZ" Then 5e$~)
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            DeleteOperation eID,count xER\ZpA:,  
            count=count-1 hjIT_{mk  
        End If {_S}H1,  
        count=count+1 (N&lHLy  
    Wend q|Qk2M  
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    'Set new z-shift >2,Gy-&"0  
    op.Type = "ShiftZ" XLL/4)  
    op.val1 = tlens D3)zk@N  
    op.parent = parID tQH+)*  
    AddOperation eID, op Sqo :-  
    Print "Set lens thickness = " & tlens rk7QZVE  
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    '************************************************************************* G.(mp<-  
    'Lens index of refraction ;gs ^%z  
    '************************************************************************* w~ [b*$  
    eID = FindMaterial( "Lens" ) '1$!jmY  
    GetModelMaterial eID, mat F0:A]`|  
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    mat.Nd = nlens |i ZfYi&^  
    SetModelMaterial eID, mat :%sXO  
    Print "Set lens index of refraction = " & nlens Ay !G1;  
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    '************************************************************************* u-tQ9ioKC  
    'Pupil diameter "m^' &L  
    '************************************************************************* HW7; {QMg
 
    eID = FindFullName( "Geometry.Arizona Eye.Pupil.Iris" ) xCYE B}o9r  
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    'Adjust pupil diameter (trimming volume inner hole) bk)g;+@  
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    SetTrimVolHole eID, pupilDiam/2, pupilDiam/2, 0, 0, "Cylinder" ]ix!tb.Q  
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    ' Adjust pupil location to just in front of the lens /__PSK  
    parID = FindFullName( "Geometry.Arizona Eye" ) gq"gUaz  
    eID = FindFullName( "Geometry.Arizona Eye.Pupil" ) {U84 _Pi  
    count = 0 MNg^]tpf  
    While GetOperationCount(eID)>count tqy@iEz+  
        GetOperation eID, count, op zLF?P3^  
        If op.Type="ShiftZ" Then A.D{.a  
            DeleteOperation eID,count ]r-C1bKD`  
            count=count-1 06Gt&_Q  
        End If /[9t`  
        count=count+1 CT\;xt,S  
    Wend b9"jtRTdz  
    op.Type = "ShiftZ" & u!\<\  
    op.val1 = taq-0.01 <&!v1yR  
    op.parent = parID I(S)n+E  
    AddOperation eID, op Q0\0f
 
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    Print "Set pupil diameter = " & pupilDiam i[ $0
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    'Update AZ Eye subassembly Description
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    eID = FindFullName( "Geometry.Arizona Eye" ) :=9]c17=  
    GetEntity eID, entity +`sv91c  
    entity.Description = "Accommodation = " & A & "D" oxj3[</'k  
    SetEntity eID, entity Sggq3l$Qc  
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    Update @vMA=v7a  
    Print "DONE!" CdUAy|!`R  
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End Sub |ea~'N1  
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如果屈光度是4，光瞳直径是4，则会输出如下数据： %hN.ktZ/s  
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Accommodation = 4 Diopters t |W)  
Pupil Diameter = 4 mm @h?shW=^  
Set aqueous humor thickness = 2.81 zKFp5H1!%+  
Set anterior lens radius = 10.4 and conic constant = -2.375869 _al|'obomy  
Set posterior lens radius = -4.424557 and conic constant = -3.081019 [~\PQYm'  
Set lens thickness = 3.927 Ro=AADv@  
Set lens index of refraction = 1.42672 |B
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Set pupil diameter = 4 ]0B|V2D#e  
DONE! as+GbstN